Hi Guys, I had this same issue but managed to resolve it, here is how I did it....
1st, remove all Line 6 soft wear on your PC or Mac.
2nd, Download the Helix Drivers, L 6 Updater, and the HX edit.
3rd, unplug the USB from your PC or Mac.
4th, restart your helix whilst pressing in buttons 1 & 6, and you should be put in update mode (sorry I can't remember the exact wording)
5th, now open HX edit and it should recognize your helix, you should also get a connection and then be able to continue with the update.
Hope this helps......
P.S. Check out the new cabs, they are excellent.